Heart Attacks
Uploaded by weiler16 on Feb 22, 2000
A heart attack occurs when the blood supply to a portion of the heart muscle is severely reduced or stopped. This happens when one of the arteries that supply blood to the heart muscle is blocked by an obstruction. This blockage can be due to a condition called atherosclerosis (a build up of fatty like substance along the wall of the artery), a blood clot or a coronary vessel spasm along with a total obstruction.
If the blood supply to a portion of the heart stops, that area of the heart will no longer receive the oxygen or nutrients needed to carry out its function and will die. If it is a very small part of the heart involved, it will be able to work without it. If a large portion is damaged, irreversible damage will happen which can lead to death.
Damage to the heart muscle may be so severe that it may cause abnormal heart rhythm, called arrhythmias. Most people who are of a myocardial infraction or a heart attack do so within a few hours due to a type of arrhythmia
The heart attack victim will complain of pressure, discomfort or a squeezing sensation in the centre of the chest. There may be pain radiating to the arms or the neck. There may also be shortness of breath, weakness, fatigue, nausea, vomiting and or indigestion. The pain that occurs is the result of heart tissue ischemia (decreased blood supply). The area that is not receiving enough blood is literally crying out for help. When a person complains of any of the symptoms mentioned, they should be transported to the nearest hospital. The diagnosis of an M.I. is made for the patient's history, from special tests on E.C.G. and measurement of certain enzymes released into the bloodstream from damaged heart muscle.
Once an M.I. has occurred and a portion of the heart muscle has died, something has to be done to prevent a piece of the obstruction from breaking off and blocking another artery somewhere else in the body. There are four main techniques to prevent this. Drugs may be given to breakdown a blood clot. The obstruction can be cleared by pushing the plaque towards the wall of the artery by inflating a balloon inside the artery (balloon angioplasty). The obstruction can be loosened up by brushing it and suctioning it out of the artery, this is called atheroectomy....